i was complete at roughly the same time you were and interviewed there in mid-october. i'm an in-state student, however- they get about 10x more applications from out-of-state, and there's more than twice as many spots available for in-state compared to out of state.
i wouldn't worry, though- they don't make most of the decisions until mid-march and interview people up until then. they do screen for secondaries, so the fact that you got one can't be a bad sign. in case you were wondering, the interview invitation comes via e-mail.
i hope this helps. good luck!